Harq process number management for downlink carrier aggregation

ABSTRACT

A method for use with a mobile user agent, the method for managing Hybrid Automatic Repeat reQuest (HARQ) processes in a multi carrier communication system that uses HARQ process indicators (HPIs) to manage HARQ processes, the method comprising the steps of designating a first subset of the HPIs as shared HPIs wherein each shared HPI designates a HARQ process irrespective of which of a plurality of system carrier frequencies are used to transmit a traffic packet, designating a second subset of the HPIs as non-carrier-shared HPIs wherein each non-carrier-shared HPI, in conjunction with the carrier frequency used to transmit a traffic packet, designates a carrier frequency unique HARQ process, receiving an HPI at the mobile user agent, receiving a first traffic packet via a carrier frequency at the user agent that is associated with the HPI, where the HPI is a first subset HPI using the HPI to identify a HARQ process associated with the first traffic packet irrespective of the carrier frequency used to transmit the traffic packet and providing the traffic packet to the identified HARQ process and where the HPI is a second subset HPI using the HPI and the carrier frequency on which the first traffic packet was received to identify a carrier frequency specific HARQ process associated with the first traffic packet and providing the first traffic packet to the carrier frequency specific HARQ process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on U.S. Provisional Patent Application Ser.No. 61/160,555 filed on Mar. 16, 2009 and entitled “HARQ PROCESS NUMBERMANAGEMENT FOR DOWNLINK CARRIER AGGREGATION.”

BACKGROUND

The present invention relates generally to data transmission in mobilecommunication systems and more specifically to methods for managing HARQprocess numbers for downlink carrier aggregation.

As used herein, the terms “user agent” and “UA” can refer to wirelessdevices such as mobile telephones, personal digital assistants, handheldor laptop computers, and similar devices that have telecommunicationscapabilities. In some embodiments, a UA may refer to a mobile, wirelessdevice. The term “UA” may also refer to devices that have similarcapabilities but that are not transportable, such as desktop computers,set-top boxes, or network nodes.

In traditional wireless telecommunications systems, transmissionequipment in a base station transmits signals throughout a geographicalregion known as a cell. As technology has evolved, more advancedequipment has been introduced that can provide services that were notpossible previously. This advanced equipment might include, for example,an enhanced node B (eNB) rather than a base station or other systems anddevices that are more highly evolved than the equivalent equipment in atraditional wireless telecommunications system. Such advanced or nextgeneration equipment may be referred to herein as long-term evolution(LTE) equipment, and a packet-based network that uses such equipment canbe referred to as an evolved packet system (EPS). additionalcharacteristics to LTE systems/equipment will eventually result in anLTE advanced (LTE-A) system. As used herein, the term “access device”will refer to any component, such as a traditional base station or anLTE or LTE-A access device, that can provide a UA with access to othercomponents in a telecommunications system.

In mobile communication systems such as the enhanced universalterrestrial radio access network (E-UTRAN), an access device providesradio access to one or more UAs. The access device comprises a packetscheduler for dynamically scheduling downlink traffic data packettransmissions and allocating uplink traffic data packet transmissionresources among all the UAs communicating to the access device. Thefunctions of the scheduler include, among others, dividing the availableair interface capacity between UAs, deciding the transport channel to beused for each UA's packet data transmissions, and monitoring packetallocation and system load. The scheduler dynamically allocatesresources for Physical Downlink Shared CHannel (PDSCH) and PhysicalUplink Shared CHannel (PUSCH) data transmissions, and sends schedulinginformation to the UAs through a scheduling channel.

Several different data control information (DCI) message formats areused by LTE access devices to communicate data packet resourceassignments to UAs including, among others, DCI formats 1 and 1A. Anaccess device selects one of the downlink DCI formats for allocatingresources to a UA as a function of several factors including UA andaccess device capabilities, the amount of data to transmit to a UA, theamount of communication traffic within a cell, channel conditions, etc.UAs refer to the scheduling/resource allocation information for thetiming and the data rate of uplink and downlink transmissions andtransmit or receive data packets accordingly. DCI formatted control datapackets are transmitted via the Physical Downlink Control CHannel(PDCCH).

Hybrid Automatic Repeat reQuest (HARQ) is a scheme for re-transmitting atraffic data packet to compensate for an incorrectly received trafficpacket. A HARQ scheme is used both in uplink and downlink in LTEsystems. Take downlink transmissions for example, for each downlinkpacket received by a UA, a positive acknowledgment (ACK) is transmittedon a Physical Uplink Control Channel (PUCCH) from the UA to the accessdevice after a cyclic redundancy check (CRC) performed by the UAindicates a successful decoding. If the CRC indicates a packet is notreceived correctly, a UA HARQ entity transmits a negativeacknowledgement (NACK) on the PUCCH in order to request a retransmissionof the erroneously received packet. Once a HARQ NACK is transmitted toan access device, the UA waits to receive a retransmitted traffic datapacket. When a retransmission request is received at an access device,the access device retransmits the incorrectly received packet to the UA.This process of transmitting, ACK/NACK and retransmitting continuesuntil either the packet is correctly received or a maximum number ofretransmissions has occurred. Hereinafter the process of transmitting aNACK, waiting for a retransmitted packet and attempting to decode theretransmitted packet will be referred to as a HARQ process.

In many cases it is desirable for an access device to transmit a largeamount of data to a UA in a short amount of time. For instance, a videocast may include large amounts of audio and video data that has to betransmitted to a UA over a short amount of time. As another instance, aUA may run several applications that all have to receive data packetsfrom an access device essentially simultaneously so that the combineddata transfer is extremely large.

One way to increase the amount of data that can be transmitted during ashort period is to have an access device commence several (e.g., five)data packet transmission processes in parallel. To facilitate a HARQscheme for each of a plurality of simultaneous packet transmissions,access devices and UAs are programmed to support parallel HARQprocesses. To this end, each DCI formatted downlink resource grant onthe PDCCH includes a three bit HARQ process number (HPN) or HARQ processindicator (HPI) corresponding to an associated data packet. When a datapacket is not correctly received, the incorrectly received packet andassociated HPI are stored by the HARQ entity in a HARQ decoding bufferand a NACK is transmitted back to the access device to requestretransmission of the data packet. The access device retransmits thedata packet along with the HPI associated with the original transmitteddata packet to the UA. When the retransmitted packet and HPI arereceived, the UA delivers the retransmitted packet to the HARQ processassociated with the received HPN. The HARQ process attempts to decodethe combined packet data and the HARQ process continues. Where the HPIis three bits, the maximum number of simultaneous HARQ processes iseight.

Another way to increase the rate of data transmission is to use multiplecarriers (i.e., multiple frequencies) to communicate between an accessdevice and UAs. Where transmission rate is increased via use of multiplecarriers, the number of separate HARQ processes required to manageadditional data should also be increased. Currently there are two knownways to increase the number of uniquely identifiable HARQ processes in amultiple carrier system. First, where multiple carriers are used, the UAHARQ entity can simply maintain separate HARQ processes for each of thecarrier frequencies in the usual fashion where the access deviceretransmits data packets using the same carrier as an originalincorrectly received packet. For instance, where the DCI format includesa three bit HPI and an access device and UA use four carriers, theaccess device and UA may facilitate eight separate HARQ processes foreach of the four carriers for a total of thirty-two separate HARQprocesses.

Second, where multiple carriers are used, the number of bits in the DCIformat for specifying the HPI can be increased and the HPI s can beshared across all carriers (i.e., any data packet can be retransmittedon any carrier irrespective of the associated HPI). For instance, wherethe HPI is five bits instead of three and an access device and UA usefour carriers, the UA can facilitate thirty-two separate HPI processesand each HPI can be facilitated using any of the carriers.

While each of the two solutions for increasing the number of supportableHARQ processes in a multiple carrier system has some advantages, eachsolution has at least one important shortcoming. The first solution thatuses a three bit HPI is advantageous because existing DCI formats anddownlink communication packets can be used which means that the controlchannel processing will be backward compatible with single carrier UAs.However, this three bit HPI solution limits access device schedulingflexibility as each HPI can only be used with a single one of thecarriers.

The second solution that uses HPIs that include more than three bitsenables more flexible scheduling of retransmissions as any carrier canbe used to retransmit packets. However, this second solution requires achange to the DCI format and subsequent packets to accommodate the fourplus bit HPI s. Changing DCI formats creates issues relating to backwardcompatibility with three bit HPI UAs and consequently increaseshypothesis testing.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of this disclosure, reference is nowmade to the following brief description, taken in connection with theaccompanying drawings and detailed description, wherein like referencenumerals represent like parts.

FIG. 1 is a schematic diagram showing components of a communicationsystem including a user agent that includes a HARQ process decodingbuffer/database;

FIG. 2 is a flow chart illustrating a process that may be performed bythe access device of FIG. 1 to enable the user agent of FIG. 1 to manageHARQ process numbers;

FIG. 3 is a flow chart illustrating a process that may be performed bythe user agent of FIG. 1 to manage HARQ process numbers;

FIG. 4 is a schematic diagram illustrating carrier states before anafter a shared HARQ process indicator is received that are consistentwith at least one aspect of the present disclosure;

FIG. 5 is a flow chart illustrating a process that may be performed bythe user agent of FIG. 1 for activating and deactivating assignedcarriers;

FIG. 6 is a flow chart illustrating a process that may be performed bythe user agent of FIG. 1 for negotiating a DCI communication format andassociated HPI bit count;

FIG. 7 is a diagram of a wireless communications system including a useragent operable for some of the various embodiments of the disclosure;

FIG. 8 is a block diagram of a user agent operable for some of thevarious embodiments of the disclosure;

FIG. 9 is a diagram of a software environment that may be implemented ona user agent operable for some of the various embodiments of thedisclosure;

FIG. 10 is an illustrative general purpose computer system suitable forsome of the various embodiments of the disclosure; and

FIG. 11 is a schematic diagram illustrating another exemplary HARQprocess buffer

DETAILED DESCRIPTION

It has been recognized that in a multicarrier communication system thatsupports Hybrid Automatic Repeat reQuest (HARQ) processes, a balancebetween flexibility and backward compatibility in managing HARQprocesses can be achieved by, without changing the downlink controlchannel (PDCCH) structure, designating a subset of HARQ process numbers(HPNs) or HARQ process indicators (HPIs) as shared and another subset asfrequency dedicated. Here, shared HPIs can be used on any frequency anduniquely designate HARQ processes irrespective of the carrier frequencyon which the HPI is used while the HARQ process associated with adedicated HPI depends on the carrier frequency on which the HPI is used.For instance, in at least some embodiments where a system includes fourcarriers and HPIs are three bit so that eight different HPIs can bespecified, two of the HPIs (e.g., 000 and 001) may be designated asshared while the other six HPIs (e.g., 010, 001, 100, 101, 110 and 111)are dedicated so that there are twenty-four dedicated HPI-channelcombinations (e.g., 6 HPI×4 separate channels) and two shared HPIs. Inthis manner, legacy communication systems that use three bit HPI do nothave to be modified to support multiple carrier communications, withrespect to control channel processing, while the shared HPI facilitateadditional flexibility at the access device.

At least some embodiments include a method for use with a mobile useragent, the method for managing Hybrid Automatic Repeat reQuest (HARQ)processes in a multi carrier communication system that uses HARQ processindicators (HPIs) to manage HARQ processes, the method comprising thesteps of, within the mobile user agent, designating a first subset ofthe HPIs as shared HPIs wherein each shared HPI designates a HARQprocess irrespective of which of a plurality of system carrierfrequencies are used to transmit a traffic packet and designating asecond subset of the HPIs as non-carrier-shared HPIs wherein eachnon-carrier-shared HPI, in conjunction with the carrier frequency usedto transmit a traffic packet, designates a carrier frequency unique HARQprocess.

In some cases the method further includes the steps of receiving an HPIat the mobile user agent, receiving a first traffic packet via a carrierfrequency at the user agent that is associated with the HPI, where theHPI is a first subset HPI, (i) using the HPI to identify a HARQ processassociated with the first traffic packet irrespective of the carrierfrequency used to transmit the traffic packet and (ii) providing thefirst traffic packet to the identified HARQ process, where the HPI is asecond subset HPI, (i) using the HPI and the carrier frequency on whichthe first traffic packet was received to identify a carrier frequencyspecific HARQ process associated with the first traffic packet and (ii)providing the first traffic packet to the carrier frequency specificHARQ process.

In some embodiments the first traffic packet is received on a firstcarrier frequency and a first HPI associated with the first trafficpacket includes a first subset HPI, the method further including thesteps of receiving a second traffic packet at the mobile user agent on asecond carrier frequency where an HPI associated with the second trafficpacket is the first HPI and, providing the second traffic packet to theHARQ process that received the first traffic packet.

In some cases the method further includes the steps of receiving thirdand fourth traffic packets via the first and second carrier frequencies,respectively, where each of the third and fourth traffic packets areassociated with a third HPI and wherein the third HPI is a second subsetHPI and providing the third and fourth traffic packets to separate HARQprocesses. In some cases the system uses four carrier frequencies andthe HPIs include eight distinct HPIs. In some embodiments the firstsubset includes two HPIs and the second subset includes six HPIs.

In some cases the method further includes the steps of, prior to thesteps of designating, receiving an HPI configuration message at the useragent indicating shared and non-shared HPI, the steps of designatingincluding using the HPI configuration message information to designatethe shared and non-shared HPI in a user agent HARQ process buffer.

Some embodiments include a method for use with a mobile user agent, themethod for managing Hybrid Automatic Repeat reQuest (HARQ) processes ina multicarrier communication system that uses HARQ process indicators(HPIs) to manage HARQ processes, the method comprising the steps of,within the mobile user agent, designating a first subset of the HPIs asshared HPIs wherein each shared HPI designates a HARQ processirrespective of which of at least first and second carrier frequenciesare used to transmit a traffic packet and designating a second subset ofthe HPIs as non-carrier-shared HPIs wherein each non-carrier-shared HPI,in conjunction with the single carrier frequency used to transmit atraffic packet, designates a carrier frequency unique HARQ process.

In some cases the method further includes receiving an HPI at the mobileuser agent, receiving a first traffic packet via a carrier frequency atthe user agent that is associated with the HPI, where the HPI is a firstsubset HPI and the carrier frequency on which the first traffic packetis received is one of the at least a first and second carrierfrequencies (i) using the HPI to identify a HARQ process associated withthe first traffic packet and at least the first and second carrierfrequencies and (ii) providing the traffic packet to the identified HARQprocess, where the HPI is a second subset HPI, (i) using the HPI and thecarrier frequency on which the first traffic packet was received toidentify a carrier frequency specific HARQ process associated with thefirst traffic packet and (ii) providing the first traffic packet to thecarrier frequency specific HARQ process.

Some embodiments include a method performed by a user agent, the methodcomprising (a) designating one carrier as an anchor carrier, (b)designating a plurality of carriers as assigned carriers, wherein atleast one of the plurality of assigned carriers is designated as aninactive carrier and (c) receiving a command on a control channel of theanchor carrier, the command resulting in changing the designation of atleast one of the at least one inactive assigned carriers to an activeassigned carrier.

In some embodiments the command is a PDCCH for a DCI packet including aparticular HPI. In some cases the method further comprises the step ofchanging the designation of the active assigned carrier to an inactiveassigned carrier after a timer expires. In some embodiments the methodfurther includes the steps of, prior to the steps of designating,receiving an HPI configuration message at the user agent indicatinganchor and assigned carriers, the steps of designating including usingthe HPI configuration message information to designate the anchor andassigned carriers.

In some cases the a method is to be performed by a user agent, themethod comprising the steps of (a) performing capability negotiationswith an access device using three bit HPI to identify a DCIformat/communication protocol and corresponding maximum HPI bit countand (b) where the maximum HPI bit count is greater than three,communicating using the maximum HPI bit count.

In some cases an embodiment includes a mobile user agent for use in amulti-carrier communication system comprising a processor programmed toperform the steps of, designating a first subset of the HPIs as sharedHPIs wherein each shared HPI designates a HARQ process irrespective ofwhich of a plurality of system carrier frequencies are used to transmita traffic packet and designating a second subset of the HPIs asnon-carrier-shared HPIs wherein each non-carrier-shared HPI, inconjunction with the carrier frequency used to transmit a trafficpacket, designates a carrier frequency unique HARQ process.

In some embodiments the processor is further programmed to perform thesteps of receiving an HPI at the mobile user agent, receiving a firsttraffic packet via a carrier frequency at the user agent that isassociated with the HPI, where the HPI is a first subset HPI, (i) usingthe HPI to identify a HARQ process associated with the first trafficpacket irrespective of the carrier frequency used to transmit thetraffic packet and (ii) providing the first traffic packet to theidentified HARQ process, where the HPI is a second subset HPI, (i) usingthe HPI and the carrier frequency on which the first traffic packet wasreceived to identify a carrier frequency specific HARQ processassociated with the first traffic packet and (ii) providing the firsttraffic packet to the carrier frequency specific HARQ process.

In some embodiments the first traffic packet is received on a firstcarrier frequency and a first HPI associated with the first trafficpacket includes a first subset HPI, the processor further programmed toperform the steps of receiving a second traffic packet at the mobileuser agent on a second carrier frequency where an HPI associated withthe second traffic packet is the first HPI and, providing the secondtraffic packet to the HARQ process that received the first trafficpacket.

Other embodiments include a user agent for use in a communicationnetwork, the user agent comprising a processor programmed to perform thesteps of (a) designating one carrier as an anchor carrier, (b)designating a plurality of carriers as assigned carriers, wherein atleast one of the plurality of assigned carriers is designated as aninactive carrier and (c) receiving a command on a control channel of theanchor carrier, the command resulting in changing the designation of atleast one of the at least one inactive assigned carriers to an activeassigned carrier.

In some embodiments the command is a PDCCH for a DCI packet including aparticular HPI. In some embodiments the processor is further programmedto perform the steps of changing the designation of the active assignedcarrier to an inactive assigned carrier after a timer expires.

Some embodiments include a user agent for use in a communication systemwherein the user agent comprises a processor programmed to perform thesteps of (a) performing capability negotiations with an access deviceusing three bit HPI to identify a DCI format/communication protocol andcorresponding maximum HPI bit count and (b) where the maximum HPI bitcount is greater than three, communicating using the maximum HPI bitcount.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described. The followingdescription and the annexed drawings set forth in detail certainillustrative aspects of the invention. However, these aspects areindicative of but a few of the various ways in which the principles ofthe invention can be employed. Other aspects, advantages and novelfeatures of the invention will become apparent from the followingdetailed description of the invention when considered in conjunctionwith the drawings.

The various aspects of the subject invention are now described withreference to the annexed drawings, wherein like numerals refer to likeor corresponding elements throughout. It should be understood, however,that the drawings and detailed description relating thereto are notintended to limit the claimed subject matter to the particular formdisclosed. Rather, the intention is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of theclaimed subject matter.

As used herein, the terms “component,” “system” and the like areintended to refer to a computer-related entity, either hardware, acombination of hardware and software, software, or software inexecution. For example, a component may be, but is not limited to being,a process running on a processor, a processor, an object, an executable,a thread of execution, a program, and/or a computer. By way ofillustration, both an application running on computer and the computercan be a component. One or more components may reside within a processand/or thread of execution and a component may be localized on onecomputer and/or distributed between two or more computers.

The word “exemplary” is used herein to mean serving as an example,instance, or illustration. Any aspect or design described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other aspects or designs.

Furthermore, the disclosed subject matter may be implemented as asystem, method, apparatus, or article of manufacture using standardprogramming and/or engineering techniques to produce software, firmware,hardware, or any combination thereof to control a computer or processorbased device to implement aspects detailed herein. The term “article ofmanufacture” (or alternatively, “computer program product”) as usedherein is intended to encompass a computer program accessible from anycomputer-readable device, carrier, or media. For example, computerreadable media can include but are not limited to magnetic storagedevices (e.g., hard disk, floppy disk, magnetic strips . . . ), opticaldisks (e.g., compact disk (CD), digital versatile disk (DVD) . . . ),smart cards, and flash memory devices (e.g., card, stick). Additionallyit should be appreciated that a carrier wave can be employed to carrycomputer-readable electronic data such as those used in transmitting andreceiving electronic mail or in accessing a network such as the Internetor a local area network (LAN). Of course, those skilled in the art willrecognize many modifications may be made to this configuration withoutdeparting from the scope or spirit of the claimed subject matter.

Referring now to the drawings wherein like reference numerals correspondto similar elements throughout the several views and more specifically,referring to FIG. 1, FIG. 1, is a schematic diagram illustrating amulti-channel communication system 30 including a user agent (UA) 10 andan access device 12. UA 10 includes, among other components, a processor14 that runs one or more software programs wherein at least one of theprograms communicates with access device 12 to receive data from, and toprovide data to, access device 12. When data is transmitted from UA 10to device 12, the data is referred to as uplink data and when data istransmitted from access device 12 to UA 10, the data is referred to asdownlink data.

To facilitate communications, a plurality of different communicationchannels are established between access device 12 and UA 10. For thepurposes of the present disclosure, referring to FIG. 1, the importantchannels between access device 12 and UA 10 include a Physical DownlinkControl CHannel (PDCCH) 70, a Physical Downlink Shared CHannel (PDSCH)72 and a Physical Uplink Control CHannel (PUCCH) 74. As the labelimplies, the PDCCH is a channel that allows access device 12 to controlUA 10 during downlink data communications. To this end, the PDCCH isused to transmit scheduling or control data packets referred to asdownlink control information (DCI) packets to the UA 10 to indicatescheduling to be used by UA 10 to receive downlink communication trafficpackets (i.e., non-control data to be used by applications run by UA10). A separate DCI packet is transmitted by access device 12 to UA 10for each of traffic packet transmitted. In addition to includinginformation indicating scheduling for an associated traffic packet, aDCI packet includes a HARQ process indicator (HPI) that can be used tofacilitate a HARQ process, if necessary, for the traffic packet.

Exemplary DCI formats including format 1 and format 1A currently used inthe E-UTRAN are described at sections 5.3.3.1.2 and 5.3.3.1.3 of 3 GPPTS 36.212 V8.3.0 (2008-05) where it can be seen that the HPI/HPN for FDDcurrently comprises a three-bit field. Thus, the HPI can have eightdistinct values. Exemplary DCI packets are indicated by communications71 and 75 on PDCCH 70 in FIG. 1.

In FIG. 1, exemplary traffic data packets on PDSCH 72 are labeled 73 and79. In at least some embodiments a traffic packet will be transmittedvia the same carrier (i.e., the same frequency) as an associated DCIpacket.

Referring to FIG. 1, the PUCCH 74 (in some cases a Physical UplinkShared CHannel (PUSCH) may be used for the uplink ACK/NACKfunctionality) is used by UA 10 to transmit acknowledgement (ACK) andnegative acknowledgement (NACK) signals (see 77 in FIG. 1) to accessdevice 12 for each of the traffic packets received to indicate eithercorrect or incorrect packet reception, respectively. Where a trafficpacket is not received correctly and a NACK is transmitted back toaccess device 12, access device 12 typically transmits another DCIpacket (see 75 in FIG. 1) and retransmits the incorrectly receivedtraffic packet (see packet 79 in FIG. 1) to UA 10.

Referring still to FIG. 1, UA processor 14 maintains a HARQ processdecoding buffer/database 22 in which incorrectly received data packetsare stored along with information that uniquely identifies one of aplurality of HARQ processes associated with the incorrectly receivedpacket(s). To this end, exemplary buffer/database 22 includes aplurality of HARQ process matrices 28, 50, 52, 54 and 56. Exemplarymatrix 50 includes six separate rows labeled HPI-010 through HPI-111 inwhich incorrectly received traffic packets may be stored. Thus, forexample, where an original traffic packet is incorrectly received, thatpacket would be stored, a second incorrectly received traffic packet(i.e., a packet retransmitted a first time) would be combined with thefirst and then stored, and so. As illustrated, matrix 50 corresponds toa first carrier frequency f1. Thus, only incorrectly received trafficpackets received on the first carrier frequency f1 are stored in matrix50. Similarly, matrices 52, 54, and 56 are associated with carrierfrequencies f2, f3, and f4, and therefore, only incorrectly receivedtraffic packets associated with carrier frequencies f2, f3 and f4 arestored in matrices 52, 54 and 56, respectively. Although notillustrated, each of matrices 52, 54 and 56 includes six rows just likematrix 50, where the rows correspond to HPIs 010, 011, 100, 101, 110 and111, respectively. Thus, for each of the HPIs 101, 011, 100, 101, 110and 111, which matrix an incorrect traffic packet is stored in is afunction of the carrier frequency used to transmit the traffic packet toUA 10. For this reason, matrices 50, 52, 54 and 56 are referred tocollectively as non-carrier-shared process matrices 25.

Referring yet again to FIG. 1, the fifth HARQ process matrix 28 includesfirst and second rows corresponding to HPIs 000, 001, respectively.Thus, an original traffic packet which is incorrectly received may bestored, an incorrectly received retransmitted packet associated with theoriginal incorrectly received packet may be combined with the first andthen stored. Here, unlike the non-carrier-shared HARQ process matrices50, 52, 54 and 56, matrix 28 is a shared HARQ process matrix whereinincorrectly received packets on all carriers f1 through f4 are includedin the same matrix 28 irrespective of the carrier used to transmit thepacket. For example, where an original packet and a subsequentlyretransmitted related packet are both associated with HARQ processindicator 000 and are received by UA 10 via first and second differentcarriers (e.g., f1, f4), the incorrectly received original andretransmitted packets are combined and then stored in matrix 28 in field36 associated with HPI 000. Thus, in this example, access device 12 canprovide HPIs to UA 10 to enable UA 10 to manage HARQ processes withouthaving to change the DCI format to accommodate more than three bits HPIsand still has the flexibility, at least with respect to HPIs 000 and001, to use any of the four system supported carrier frequencies f1through f4.

It should be appreciated that, while the example here includes sixnon-carrier-shared HPI values and two carrier shared HPI values, othercombinations of shared and non-carrier-shared HPIs are contemplated.Thus, in some cases it may be desirable to have four carrier-shared andfour non-carrier-shared HPIs or two non-carrier-shared and six carriedshared HPIs. To configure buffer/database, it is contemplated that in atleast some embodiments access device 12 (see again FIG. 1) may beprogrammed to transmit an HPI configuration message to UA 10 indicatingshared and non-shared HPI. For instance, an exemplary HPI configurationmessage may include a 19 bit field where the first sixteen bits indicatea specific UA 10 and the last three bits indicate one of eight three bitcombinations. Here, UA 10 may be programmed to interpret the last threebits as indicating that all HPI associated with bit combinations smallerthan and including the three bit combination should be treated as sharedHPI. For instance, where the last three bits include 000, HPI 000 wouldbe treated as shared while the balance of HPI including 001 through 111would be treated as non-shared. Similarly, where the last three bitsinclude 001, HPI 000 and 001 would be treated as shared while thebalance of HPI including 010 through 111 would be treated as non-shared.Other HPI configuration messages are contemplated. In at least someembodiments the HPI configuration message may be transmitted via theRadio Resource Control (RRC) layer, the broadcast control channel or theMAC control elements of E-UTRAN that are associated with the radiointerface.

In other embodiments it is contemplated that the HPI configurationmessage may be periodically broadcast from an access device 12 to allUAs in the vicinity to configure HPI buffers as with shared andnon-shared HPI matrices. Here, the shared and non-shared configurationmay be altered by an access device 12 periodically to optimally addressconditions throughout a communication system.

Referring now to FIG. 2, a process 90 performed by access device 12 forfacilitating HARQ process management by UA 10 is illustrated. Atdecision block 100, access device 12 determines whether or not downlinkdata transmission to UA 10 is required. Where downlink transmission isnot required, control continues to loop back through decision block 100.Once downlink transmission is required, control passes to block 102where access device 12 identifies an available HPI or HPI/carriercombination. Here, it should be appreciated that access device 12 keepstrack of HPIs or HPI/carrier combinations currently being used with UA10 to track previously transmitted traffic packets. At block 102, accessdevice 12 selects one of the available (i.e., currently unused) HPI orHPI/carrier combinations. Continuing and referring also to FIG. 1, atprocess block 106, access device 12 creates and transmits a DCI packet71 including the HPI identified at block 102 to the UA 10. Where theavailable HPI selected is a carrier shared HPI, the access deviceselects anyone of the carrier frequencies for the DCI packet. Where theavailable HPI is a non-carrier shared HPI, the access device 12 selectsa specific one of the carriers associated with the HPI for the DCIpacket. At process block 108, access device 12 transmits a trafficpacket to UA 10 (see 73 in FIG. 1) using the DCI specific schedule andthe selected carrier frequency and at block 110 access device 12monitors the PUCCH for an ACK or a NACK. At block 112, when an ACK isreceived (see 77 in FIG. 1), control passes to block 114 where accessdevice 12 renders the HPI or HPI/channel combination associated with thereceived ACK available. After block 114, control passes back up to block100.

Referring still to FIGS. 1 and 2, at block 112, if an ACK is notreceived, control passes to block 116 where access device 12 determineswhether or not a NACK has been received. Where no NACK has beenreceived, control passes to block 110 where access device 12 continuesto monitor the PUCCH for an ACK or a NACK. At block 116, where a NACKhas been received, control passes to block 118 where access device 12transmits another DCI packet (see 75 in FIG. 1) including the originalHPI and retransmits the traffic packet (see 79 in FIG. 1) incorrectlyreceived by the UA 10. After block 118, control passes back to block 110to monitor for another ACK/NACK. The FIG. 3 process is performed foreach original traffic packet to transmit to a UA and multiple processeslike process 90 may be performed simultaneously.

Referring now to FIG. 3, a process 190 performed by the UA processor 14in FIG. 1 for managing HARQ processes is illustrated. Process 190 isperformed, in part, in parallel with the process shown and describedabove with respect to FIG. 2. Referring also to FIG. 1, at process block200 carrier shared and carrier dedicated HPIs are defined or specifiedfor a HARQ management application/entity on UA 10. As shown in FIG. 1,in the exemplary embodiment, the carrier shared HPIs include 000 and 001that are associated with HARQ matrix 28 and that are shared among eachof the four frequencies f1 through f4. The exemplary non-carrier-sharedHPIs in FIG. 1 include HPIs 010, 011, 100, 101, 110 and 111, each ofwhich, in combination with a specific one of the carrier frequencies f1,f2, f3 or f4, uniquely identifies a HARQ process.

Referring still to FIGS. 1 and 3, at decision block 202, UA processor 14monitors the PDCCH for a DCI packet. At block 204, once a DCI packet isreceived (see 71 in FIG. 1), control passes to block 206 where UAprocessor 14 identifies the downlink resource scheduled in the DCIpacket. Here, in addition to identifying the downlink resourcescheduled, processor 14 can use the DCI packet information to determinewhether or not the traffic packet associated with the resource grant isnew data or retransmitted data by examining a new data indicator (NDI)which is provided for that purpose. In addition, at block 206, processor14 can identify the HPI specified by the DCI packet information. Atblock 207, processor 14 accesses the traffic packet transmitted (see 73in FIG. 1) to the UA 10 via the resource grant identified at block 206.

At decision block 208, processor 14 determines whether or not the NDI inthe DCI indicates new data. Where the NDI indicates new data, controlpasses to decision block 210 where processor 14 determines whether ornot the new data or original traffic packet was received correctly.Where the original traffic packet is received correctly, at block 212,processor 14 transmits an ACK (see 77 FIG. 1) back to access device 12after which control passes back up to block 202 where processor 14continues to monitor for new DCI on the PDCCH.

Referring to FIGS. 1 and 3, at decision block 210, if the originaltraffic packet is incorrectly received, control passes to block 215where processor 14 determines whether or not the HPI specified by theDCI is shared by the carriers or is non-carrier-shared. Again, in thepresent example illustrated in FIG. 1, HPIs 000 and 001 are both sharedcarriers while HPIs 010, 011, 100, 101, 110 and 111 are allnon-carrier-shared. Where the HPI is shared by carriers, control passesto block 217 where the incorrectly received original packet isassociated with the shared HPI and is stored to the HARQ decoding bufferin the appropriate shared HARQ process matrix 28. For instance, in theexample illustrated in FIG. 1, where a DCI specified HPI includes sharedHPI 000, regardless of which frequency was used to transmit the trafficpacket to UA 10, at block 217 (see again FIG. 3) the incorrectlyreceived original packet is stored in field 24 corresponding to HPI 000.After block 217, control passes to block 216 where processor 14transmits a NACK to access device 12 thereby requesting that accessdevice 12 retransmit the original traffic packet. After block 216,control passes back up to block 202.

Referring once again to FIGS. 1 and 3, at block 215, where the HPI is anon-carrier-shared HPI, control passes to block 214 where processor 14identified the carrier used to transmit the received traffic packet andthe incorrectly received original packet is associated with the HPIspecified by the DCI and the traffic packet carrier combination, and thepacket is stored in the appropriate HARQ decoding buffer (i.e., thebuffer associated with the HPI/carrier combination). For instance,consistent with the above example described with respect to FIG. 1,where the HPI is 100 and therefore is a non-carrier-shared HPI and thetraffic packet carrier frequency is f1, the incorrectly receivedoriginal traffic packet is stored to field 51 corresponding to HPI 100in matrix 50 that is associated with frequency f1. After block 214,control passes to block 216 where processor 14 transmits a NACK (see 77in FIG. 1) to access device 12 after which control passes back up toblock 202.

Referring yet again to FIGS. 1 and 3, at block 208, where the NDIindicates a retransmitted packet, control passes to block 222. At block222, processor 14 determines whether or not the HPI is shared ornon-carrier-shared. Where the HPI is shared by the carriers, controlpasses to block 224 where the retransmitted packet is associated withthe shared HPI and is stored to the appropriate HARQ decoding buffer.Again, consistent with the FIG. 1 example, where the HPI is 000 andtherefore is a shared HPI, the retransmitted packet is combined with theoriginal packet and stored in the HPI 000 row in matrix 28. After block224, control passes to block 228.

Referring again to decision block 222, where the HPI non-carrier-shared,control passes to block 226 where processor 14 identifies the carrierused to transmit the received traffic packet and the retransmittedpacket is associated with the HPI specified in the DCI and the trafficpacket carrier combination and the packet is stored to the carrierspecific HARQ matrix in buffer 22. After block 226, control passes toblock 228.

Referring still to FIGS. 1 and 3, at block 228, processor 14 uses all ofthe packets (i.e., the original packet and any retransmitted packets)stored in the HARQ process decoding buffer 22 that are associated withthe HPI and carrier combination or the HPI (in the case of carriershared HPIs) to attempt to decode the related packets. At block 230,where the packets are correctly decoded, control passes to block 232where processor 14 transmits an ACK (see 77 in FIG. 1) to access device12 indicating that the data associated with the correctly decodedpackets has been correctly received. At block 234, processor 14 clearsthe data associated with the HPI or HPI/carrier combination from theHARQ decoding buffer so that the HPI or HPI/carrier combination can beused thereafter to track a subsequent HARQ process. In the alternative,in at least some embodiments, it is contemplated that the clearing step234 would not be performed and instead that the HPI or HPI/carriercombination would simply be reused when access device 12 transmits asubsequent DCI indicating new data (via the NDI) and specifying the HPIor HPI/carrier combination. Where the packets are not correctly decodedat block 230, control passes back to block 216 where UA 10 transmits aNACK to access device 12 thereby requesting that the original packetagain be retransmitted.

Where a communication system employs multiple carriers, UA battery powercan be conserved by controlling the UA to only monitor a subset of thecarriers when certain operating characteristics occur. For example,where a communication system employs four carrier frequencies f1, f2, f3and f4, during a low traffic operation, it may be that only one of thefour carriers has to be used for downlink purposes so that the otherthree frequencies need not be monitored. To this end, systems alreadyhave been contemplated wherein a UA 10 can monitor one anchor carrierroutinely during low traffic operation and, when conditions warrant, maybe controlled to monitor more than one or all of the carriers tofacilitate faster download of data. Here, one requirement is to providessome way for an access device 12 (see again FIG. 1) to indicate to a UA10 when multiple carriers should be monitored. It has been recognizedthat a shared HPI can be used as an indicator to a UA 10 to monitormultiple carriers.

Referring now to FIG. 4, consistent with the above comments, fourcarriers 402, 404, 406 and 408 that are used within an exemplarycommunication system are illustrated. The carriers corresponding tofrequencies f1, f2, f3 and f4, respectively. As shown, carrier 406corresponding to frequency f3 is referred to as an anchor carriermeaning that carrier 406 is the only carrier routinely monitored by UA10. Carriers 204 and 208 corresponding to frequencies f1 and f4 aredesignated as inactive assigned carriers meaning that these are carriersthat are assigned by the access device 12 to UA 10 where the carriersare initially designated as inactive. However, after UA 10 receives acommand on the control channel of anchor carrier 406, the assignedcarriers become active assigned carriers as shown at 402 a and 408 a inFIG. 4. Once an assigned carrier becomes active, the UA 10 begins tomonitor the control channels on the active assigned carriers as well asmonitoring the anchor carrier control channel. The “not assigned”carrier 404 corresponding to frequency f2 is ignored by the UA 10 untilthe UA 10 is explicitly instructed to reclassify the carrier 404 as anassigned carrier.

Referring still to FIG. 4, according to another aspect of at least someembodiments of the present disclosure, when UA 10 receives a controlchannel message on the anchor carrier 406 that contains one of theshared HARQ process numbers (e.g., 000 or 001 in the FIG. 1 example),the UA processor 14 begins to monitor the control channels on theassigned carriers so the assigned carriers all become active asindicated at 402 a and 408 a in FIG. 4. In FIG. 4, reception of a sharedHPI is indicated at time 410.

After assigned carriers have been rendered active, it is contemplatedthat conditions may occur in which the UA 10 should revert back tomonitoring only the anchor carrier and therefore the assigned carriersshould again be rendered inactive. In at least some embodiments it iscontemplated that, after assigned carriers are rendered active, if athreshold time period occurs without any control channel messages on theassigned carriers, UA 10 may be programmed to automatically inactivatethe assigned carriers so that only the anchor carrier is monitored.

Referring now to FIG. 5 and again to FIG. 1, a method 500 by which UA 10activates and deactivates carriers as a function of shared HPI isillustrated. At block 502, UA processor 14 designates anchor, assignedand not assigned carriers. Here, the designation step 502 may becontrolled by access device 12. At block 504, a maximum timer value isset. At block 506, UA processor 14 monitors the anchor carrier PDCCH fora DCI packet including a shared HPI. At decision block 508, where a DCIpacket is received, control passes to block 510 where the DCI isprocessed. At block 512, the DCI HPI is identified. At block 514, wherethe HPI is non-carrier-shared control passes back up to block 506 wheremonitoring of the anchor carrier PDCCH continues. At block 514, wherethe HPI is shared, control passes to block 516 where a timer is started.

Referring still to FIGS. 1 and 5, at block 518, processor 14 monitorsthe PDCCH of the anchor carrier and the active assigned carriers (i.e.,the assigned carriers are rendered active). At decision block 520,processor 14 determines whether or not a DCI packet has been received onone of the assigned carriers. Where a DCI packet has been received onone of the active assigned carriers, control passes to block 528 wherethe timer is reset to zero and control passes to block 516 where thetimer is restarted. At block 520, where no DCI packet is received on theassigned carriers, control passes to decision block 522. At block 522,processor 14 determines whether or not the timer has reached the maximumtimer value. Where the timer has not reached a maximum timer value,control passes back to block 518 where the anchor and assigned carrierchannels are monitored. Where the timer reaches the maximum timer valueat block 522, control passes to block 524 where processor 14 renders theassigned carriers inactive. At block 526, processor 14 resets the timerto zero and control passes back up to block 506 where the processdescribed above continues.

Thus, it should be appreciated that as long as at least one DCI packetis received on one of the assigned carriers prior to the maximum timervalue expiring, processor 14 will continue to monitor the controlchannels of the assigned carriers (i.e., the assigned carriers willremain active). However, once the maximum timer value times out withouta DCI packet being received on one of the assigned carriers, theassigned carriers will be inactivated.

In at least some cases it is contemplated that, while some UA's may onlybe able to employ three-bit HPIs, enhancements to communicationprotocols and future UA's may enable some of those future UA's to employHPIs having four or more bits. Here, where a system has to supportlegacy three bit HPI UA's as well as UA's that can use four or more bitHPIs, an access devices will have to perform capability negotiationswith a UA prior to settling on an optimal DCI communication and HPI bitnumber protocol. To this end, according to another aspect of at leastsome embodiments of the present disclosure, when an access device firstbegins communication with a UA, the access device will use a DCIprotocol including the legacy three bit HPI and, thereafter, if the UA10 indicates that the UA 10 can communicate via a more optimal DCIprotocol including four or more HPI bits, the communication protocolbetween the access device and the UA will be altered.

Consistent with the comments in the previous paragraph, a process 600that may be performed by UA 10 is illustrated. At block 602, UAprocessor 14 performs capability negotiations with an access device 12using three bit HPI to identify an optimal DCI format/communicationprotocol and corresponding maximum UA 10 HPI bit count. At block 604,where the maximum HPI bit count is greater than three, control passes toblock 608 where UA 10 begins communicating using the higher bit countHPI. Where the maximum HPI bit count is not greater than three, controlpasses to block 606 where normal operation with three bit HPI continues.

FIG. 7 illustrates a wireless communications system including anembodiment of the UA 10. The UA 10 is operable for implementing aspectsof the disclosure, but the disclosure should not be limited to theseimplementations. Though illustrated as a mobile phone, the UA 10 maytake various forms including a wireless handset, a pager, a personaldigital assistant (PDA), a portable computer, a tablet computer, alaptop computer. Many suitable devices combine some or all of thesefunctions. In some embodiments of the disclosure, the UA 10 is not ageneral purpose computing device like a portable, laptop or tabletcomputer, but rather is a special-purpose communications device such asa mobile phone, a wireless handset, a pager, a PDA, or atelecommunications device installed in a vehicle. The UA 10 may also bea device, include a device, or be included in a device that has similarcapabilities but that is not transportable, such as a desktop computer,a set-top box, or a network node. The UA 10 may support specializedactivities such as gaming, inventory control, job control, and/or taskmanagement functions, and so on.

The UA 10 includes a display 702. The UA 10 also includes atouch-sensitive surface, a keyboard or other input keys generallyreferred as 704 for input by a user. The keyboard may be a full orreduced alphanumeric keyboard such as QWERTY, Dvorak, AZERTY, andsequential types, or a traditional numeric keypad with alphabet lettersassociated with a telephone keypad. The input keys may include atrackwheel, an exit or escape key, a trackball, and other navigationalor functional keys, which may be inwardly depressed to provide furtherinput function. The UA 10 may present options for the user to select,controls for the user to actuate, and/or cursors or other indicators forthe user to direct.

The UA 10 may further accept data entry from the user, including numbersto dial or various parameter values for configuring the operation of theUA 10. The UA 10 may further execute one or more software or firmwareapplications in response to user commands. These applications mayconfigure the UA 10 to perform various customized functions in responseto user interaction. Additionally, the UA 10 may be programmed and/orconfigured over-the-air, for example from a wireless base station, awireless access point, or a peer UA 10.

Among the various applications executable by the UA 10 are a webbrowser, which enables the display 702 to show a web page. The web pagemay be obtained via wireless communications with a wireless networkaccess node, a cell tower, a peer UA 10, or any other wirelesscommunication network or system 700. The network 700 is coupled to awired network 708, such as the Internet. Via the wireless link and thewired network, the UA 10 has access to information on various servers,such as a server 710. The server 710 may provide content that may beshown on the display 702. Alternately, the UA 10 may access the network700 through a peer UA 10 acting as an intermediary, in a relay type orhop type of connection.

FIG. 8 shows a block diagram of the UA 10. While a variety of knowncomponents of UAs 110 are depicted, in an embodiment a subset of thelisted components and/or additional components not listed may beincluded in the UA 10. The UA 10 includes a digital signal processor(DSP) 802 and a memory 804. As shown, the UA 10 may further include anantenna and front end unit 806, a radio frequency (RF) transceiver 808,an analog baseband processing unit 810, a microphone 812, an earpiecespeaker 814, a headset port 816, an input/output interface 818, aremovable memory card 820, a universal serial bus (USB) port 822, ashort range wireless communication sub-system 824, an alert 826, akeypad 828, a liquid crystal display (LCD), which may include a touchsensitive surface 830, an LCD controller 832, a charge-coupled device(CCD) camera 834, a camera controller 836, and a global positioningsystem (GPS) sensor 838. In an embodiment, the UA 10 may include anotherkind of display that does not provide a touch sensitive screen. In anembodiment, the DSP 802 may communicate directly with the memory 804without passing through the input/output interface 818.

The DSP 802 or some other form of controller or central processing unitoperates to control the various components of the UA 10 in accordancewith embedded software or firmware stored in memory 804 or stored inmemory contained within the DSP 802 itself. In addition to the embeddedsoftware or firmware, the DSP 802 may execute other applications storedin the memory 804 or made available via information carrier media suchas portable data storage media like the removable memory card 820 or viawired or wireless network communications. The application software maycomprise a compiled set of machine-readable instructions that configurethe DSP 802 to provide the desired functionality, or the applicationsoftware may be high-level software instructions to be processed by aninterpreter or compiler to indirectly configure the DSP 802.

The antenna and front end unit 806 may be provided to convert betweenwireless signals and electrical signals, enabling the UA 10 to send andreceive information from a cellular network or some other availablewireless communications network or from a peer UA 10. In an embodiment,the antenna and front end unit 806 may include multiple antennas tosupport beam forming and/or multiple input multiple output (MIMO)operations. As is known to those skilled in the art, MIMO operations mayprovide spatial diversity which can be used to overcome difficultchannel conditions and/or increase channel throughput. The antenna andfront end unit 806 may include antenna tuning and/or impedance matchingcomponents, RF power amplifiers, and/or low noise amplifiers.

The RF transceiver 808 provides frequency shifting, converting receivedRF signals to baseband and converting baseband transmit signals to RF.In some descriptions a radio transceiver or RF transceiver may beunderstood to include other signal processing functionality such asmodulation/demodulation, coding/decoding, interleaving/deinterleaving,spreading/despreading, inverse fast Fourier transforming (IFFT)/fastFourier transforming (FFT), cyclic prefix appending/removal, and othersignal processing functions. For the purposes of clarity, thedescription here separates the description of this signal processingfrom the RF and/or radio stage and conceptually allocates that signalprocessing to the analog baseband processing unit 810 and/or the DSP 802or other central processing unit. In some embodiments, the RFTransceiver 808, portions of the Antenna and Front End 806, and theanalog baseband processing unit 810 may be combined in one or moreprocessing units and/or application specific integrated circuits(ASICs).

The analog baseband processing unit 810 may provide various analogprocessing of inputs and outputs, for example analog processing ofinputs from the microphone 812 and the headset 816 and outputs to theearpiece 814 and the headset 816. To that end, the analog basebandprocessing unit 810 may have ports for connecting to the built-inmicrophone 812 and the earpiece speaker 814 that enable the UA 10 to beused as a cell phone. The analog baseband processing unit 810 mayfurther include a port for connecting to a headset or other hands-freemicrophone and speaker configuration. The analog baseband processingunit 810 may provide digital-to-analog conversion in one signaldirection and analog-to-digital conversion in the opposing signaldirection. In some embodiments, at least some of the functionality ofthe analog baseband processing unit 810 may be provided by digitalprocessing components, for example by the DSP 802 or by other centralprocessing units.

The DSP 802 may perform modulation/demodulation, coding/decoding,interleaving/deinterleaving, spreading/despreading, inverse fast Fouriertransforming (IFFT)/fast Fourier transforming (FFT), cyclic prefixappending/removal, and other signal processing functions associated withwireless communications. In an embodiment, for example in a codedivision multiple access (CDMA) technology application, for atransmitter function the DSP 802 may perform modulation, coding,interleaving, and spreading, and for a receiver function the DSP 802 mayperform despreading, deinterleaving, decoding, and demodulation. Inanother embodiment, for example in an orthogonal frequency divisionmultiplex access (OFDMA) technology application, for the transmitterfunction the DSP 802 may perform modulation, coding, interleaving,inverse fast Fourier transforming, and cyclic prefix appending, and fora receiver function the DSP 802 may perform cyclic prefix removal, fastFourier transforming, deinterleaving, decoding, and demodulation. Inother wireless technology applications, yet other signal processingfunctions and combinations of signal processing functions may beperformed by the DSP 802.

The DSP 802 may communicate with a wireless network via the analogbaseband processing unit 810. In some embodiments, the communication mayprovide Internet connectivity, enabling a user to gain access to contenton the Internet and to send and receive e-mail or text messages. Theinput/output interface 818 interconnects the DSP 802 and variousmemories and interfaces. The memory 804 and the removable memory card820 may provide software and data to configure the operation of the DSP802. Among the interfaces may be the USB interface 822 and the shortrange wireless communication sub-system 824. The USB interface 822 maybe used to charge the UA 10 and may also enable the UA 10 to function asa peripheral device to exchange information with a personal computer orother computer system. The short range wireless communication sub-system824 may include an infrared port, a Bluetooth interface, an IEEE 802.11compliant wireless interface, or any other short range wirelesscommunication sub-system, which may enable the UA 10 to communicatewirelessly with other nearby mobile devices and/or wireless basestations.

The input/output interface 818 may further connect the DSP 802 to thealert 826 that, when triggered, causes the UA 10 to provide a notice tothe user, for example, by ringing, playing a melody, or vibrating. Thealert 826 may serve as a mechanism for alerting the user to any ofvarious events such as an incoming call, a new text message, and anappointment reminder by silently vibrating, or by playing a specificpre-assigned melody for a particular caller.

The keypad 828 couples to the DSP 802 via the interface 818 to provideone mechanism for the user to make selections, enter information, andotherwise provide input to the UA 10. The keyboard 828 may be a full orreduced alphanumeric keyboard such as QWERTY, Dvorak, AZERTY andsequential types, or a traditional numeric keypad with alphabet lettersassociated with a telephone keypad. The input keys may include atrackwheel, an exit or escape key, a trackball, and other navigationalor functional keys, which may be inwardly depressed to provide furtherinput function. Another input mechanism may be the LCD 830, which mayinclude touch screen capability and also display text and/or graphics tothe user. The LCD controller 832 couples the DSP 802 to the LCD 830.

The CCD camera 834, if equipped, enables the UA 10 to take digitalpictures. The DSP 802 communicates with the CCD camera 834 via thecamera controller 836. In another embodiment, a camera operatingaccording to a technology other than Charge Coupled Device cameras maybe employed. The GPS sensor 838 is coupled to the DSP 802 to decodeglobal positioning system signals, thereby enabling the UA 10 todetermine its position. Various other peripherals may also be includedto provide additional functions, e.g., radio and television reception.

FIG. 9 illustrates a software environment 902 that may be implemented bythe DSP 802. The DSP 802 executes operating system drivers 904 thatprovide a platform from which the rest of the software operates. Theoperating system drivers 904 provide drivers for the UA hardware withstandardized interfaces that are accessible to application software. Theoperating system drivers 904 include application management services(“AMS”) 906 that transfer control between applications running on the UA10. Also shown in FIG. 10 are a web browser application 908, a mediaplayer application 910, and Java applets 912. The web browserapplication 908 configures the UA 10 to operate as a web browser,allowing a user to enter information into forms and select links toretrieve and view web pages. The media player application 910 configuresthe UA 10 to retrieve and play audio or audiovisual media. The Javaapplets 912 configure the UA 10 to provide games, utilities, and otherfunctionality. A component 914 might provide functionality describedherein.

The UA 10, access device 120, and other components described above mightinclude a processing component that is capable of executing instructionsrelated to the actions described above. FIG. 10 illustrates an exampleof a system 1000 that includes a processing component 1010 suitable forimplementing one or more embodiments disclosed herein. In addition tothe processor 1010 (which may be referred to as a central processor unit(CPU or DSP), the system 1000 might include network connectivity devices1020, random access memory (RAM) 1030, read only memory (ROM) 1040,secondary storage 1050, and input/output (I/O) devices 1060. In someembodiments, a program for implementing the determination of a minimumnumber of HARQ process IDs may be stored in ROM 1040. In some cases,some of these components may not be present or may be combined invarious combinations with one another or with other components notshown. These components might be located in a single physical entity orin more than one physical entity. Any actions described herein as beingtaken by the processor 1010 might be taken by the processor 1010 aloneor by the processor 1010 in conjunction with one or more componentsshown or not shown in the drawing.

The processor 1010 executes instructions, codes, computer programs, orscripts that it might access from the network connectivity devices 1020,RAM 1030, ROM 1040, or secondary storage 1050 (which might includevarious disk-based systems such as hard disk, floppy disk, or opticaldisk). While only one processor 1010 is shown, multiple processors maybe present. Thus, while instructions may be discussed as being executedby a processor, the instructions may be executed simultaneously,serially, or otherwise by one or multiple processors. The processor 1010may be implemented as one or more CPU chips.

The network connectivity devices 1020 may take the form of modems, modembanks, Ethernet devices, universal serial bus (USB) interface devices,serial interfaces, token ring devices, fiber distributed data interface(FDDI) devices, wireless local area network (WLAN) devices, radiotransceiver devices such as code division multiple access (CDMA)devices, global system for mobile communications (GSM) radio transceiverdevices, worldwide interoperability for microwave access (WiMAX)devices, and/or other well-known devices for connecting to networks.These network connectivity devices 1020 may enable the processor 1010 tocommunicate with the Internet or one or more telecommunications networksor other networks from which the processor 1010 might receiveinformation or to which the processor 1010 might output information.

The network connectivity devices 1020 might also include one or moretransceiver components 1025 capable of transmitting and/or receivingdata wirelessly in the form of electromagnetic waves, such as radiofrequency signals or microwave frequency signals. Alternatively, thedata may propagate in or on the surface of electrical conductors, incoaxial cables, in waveguides, in optical media such as optical fiber,or in other media. The transceiver component 1025 might include separatereceiving and transmitting units or a single transceiver. Informationtransmitted or received by the transceiver 1025 may include data thathas been processed by the processor 1010 or instructions that are to beexecuted by processor 1010. Such information may be received from andoutputted to a network in the form, for example, of a computer databaseband signal or signal embodied in a carrier wave. The data may beordered according to different sequences as may be desirable for eitherprocessing or generating the data or transmitting or receiving the data.The baseband signal, the signal embedded in the carrier wave, or othertypes of signals currently used or hereafter developed may be referredto as the transmission medium and may be generated according to severalmethods well known to one skilled in the art.

The RAM 1030 might be used to store volatile data and perhaps to storeinstructions that are executed by the processor 1010. The ROM 1040 is anon-volatile memory device that typically has a smaller memory capacitythan the memory capacity of the secondary storage 1050. ROM 1040 mightbe used to store instructions and perhaps data that are read duringexecution of the instructions. Access to both RAM 1030 and ROM 1040 istypically faster than to secondary storage 1050. The secondary storage1050 is typically comprised of one or more disk drives or tape drivesand might be used for non-volatile storage of data or as an over-flowdata storage device if RAM 1030 is not large enough to hold all workingdata. Secondary storage 1050 may be used to store programs that areloaded into RAM 1030 when such programs are selected for execution.

The I/O devices 1060 may include liquid crystal displays (LCDs), touchscreen displays, keyboards, keypads, switches, dials, mice, track balls,voice recognizers, card readers, paper tape readers, printers, videomonitors, or other well-known input devices. Also, the transceiver 1025might be considered to be a component of the I/O devices 1060 instead ofor in addition to being a component of the network connectivity devices1020. Some or all of the I/O devices 1060 may be substantially similarto various components depicted in the previously described drawing ofthe UA 10, such as the display 702 and the input 704.

The following 3rd Generation Partnership Project (3GPP) TechnicalSpecifications (TS) are incorporated herein by reference: TS 36.321, TS36.331, and TS 36.300.

While several embodiments have been provided in the present disclosure,it should be understood that the disclosed systems and methods may beembodied in many other specific forms without departing from the spiritor scope of the present disclosure. The present examples are to beconsidered as illustrative and not restrictive, and the intention is notto be limited to the details given herein. For example, the variouselements or components may be combined or integrated in another systemor certain features may be omitted, or not implemented.

Also, techniques, systems, subsystems and methods described andillustrated in the various embodiments as discrete or separate may becombined or integrated with other systems, modules, techniques, ormethods without departing from the scope of the present disclosure.Other items shown or discussed as coupled or directly coupled orcommunicating with each other may be indirectly coupled or communicatingthrough some interface, device, or intermediate component, whetherelectrically, mechanically, or otherwise. Other examples of changes,substitutions, and alterations are ascertainable by one skilled in theart and could be made without departing from the spirit and scopedisclosed herein.

In addition, while the example described above with respect to FIG. 1includes carrier shared HPI and non-carrier-shared HPI, some embodimentsare contemplated that include partially shared HPI. For instance, an HPImay be shared among a subset of system frequencies where the balance ofsystem frequencies each combine with the HPI to specify specific HARQprocesses. For example, referring to FIG. 11, an exemplary set 1100 ofmatrices 1102-1108 that form an alternate process decoding buffer areillustrated. In FIG. 11, matrix 1102 indicates that HPI 000, 001, 010and 011 are shared for frequencies f1 and f2. Here, however, matrices1106 and 1108 indicate that for frequencies f3 and f4 the HPI 000, 001,010 and 011 are not shared. In addition, matrices 1104, 1105, 1106 and1108 indicate that each of HPI 100, 101, 110 and 111 arenon-carrier-shared.

In the FIG. 11 example, in addition to identifying HPI, the UA processor14 would have to always identify traffic packet carrier (i.e.,transmission frequency). Where any of the partially shared HPI 000, 001,010 or 011 is received, frequency f1 and f2 traffic packets incorrectlyreceived are stored by HPI in matrix 1102. Where any of partially sharedHPI 000, 001, 010 or 011 is received, frequency f3 or f4 traffic packetsincorrectly received are stored by HPI in matrix 1106 and 1108,respectively.

To apprise the public of the scope of this invention, the followingclaims are made:

1. A method for use with a mobile user agent, the method for managingHybrid Automatic Repeat reQuest (HARQ) processes in a multi carriercommunication system that uses HARQ process indicators (HPIs) to manageHARQ processes, the method comprising the steps of, within the mobileuser agent: designating a first subset of the HPIs as shared HPIswherein each shared HPI designates a HARQ process irrespective of whichof a plurality of system carrier frequencies are used to transmit atraffic packet; and designating a second subset of the HPIs asnon-carrier-shared HPIs wherein each non-carrier-shared HPI, inconjunction with the carrier frequency used to transmit a trafficpacket, designates a carrier frequency unique HARQ process.
 2. Themethod of claim 1 further including the steps of: receiving an HPI atthe mobile user agent; receiving a first traffic packet via a carrierfrequency at the user agent that is associated with the HPI; where theHPI is a first subset HPI: (i) using the HPI to identify a HARQ processassociated with the first traffic packet irrespective of the carrierfrequency used to transmit the traffic packet; and (ii) providing thefirst traffic packet to the identified HARQ process; where the HPI is asecond subset HPI: (i) using the HPI and the carrier frequency on whichthe first traffic packet was received to identify a carrier frequencyspecific HARQ process associated with the first traffic packet; and (ii)providing the first traffic packet to the carrier frequency specificHARQ process.
 3. The method of claim 2 wherein the first traffic packetis received on a first carrier frequency and a first HPI associated withthe first traffic packet includes a first subset HPI, the method furtherincluding the steps of receiving a second traffic packet at the mobileuser agent on a second carrier frequency where an HPI associated withthe second traffic packet is the first HPI and, providing the secondtraffic packet to the HARQ process that received the first trafficpacket.
 4. The method of claim 3 further including the steps of:receiving third and fourth traffic packets via the first and secondcarrier frequencies, respectively, where each of the third and fourthtraffic packets are associated with a third HPI and wherein the thirdHPI is a second subset HPI; and providing the third and fourth trafficpackets to separate HARQ processes.
 5. The method of claim 1 wherein thesystem uses four carrier frequencies and the HPIs include eight distinctHPIs.
 6. The method of claim 5 wherein the first subset includes twoHPIs and the second subset includes six HPIs.
 7. The method of claim 1further including the steps of, prior to the steps of designating,receiving an HPI configuration message at the user agent indicatingshared and non-shared HPI, the steps of designating including using theHPI configuration message information to designate the shared andnon-shared HPI in a user agent HARQ process buffer.
 8. A methodperformed by a user agent, the method comprising: a. designating onecarrier as an anchor carrier; b. designating a plurality of carriers asassigned carriers, wherein at least one of the plurality of assignedcarriers is designated as an inactive carrier; and c. receiving acommand on a control channel of the anchor carrier, the commandresulting in changing the designation of at least one of the at leastone inactive assigned carriers to an active assigned carrier.
 9. Themethod of claim 8 wherein the command is a PDCCH for a DCI packetincluding a particular HPI.
 10. The method of claim 8 further comprisingthe step of changing the designation of the active assigned carrier toan inactive assigned carrier after a timer expires.
 11. The method ofclaim 8 further including the steps of, prior to the steps ofdesignating, receiving an HPI configuration message at the user agentindicating anchor and assigned carriers, the steps of designatingincluding using the HPI configuration message information to designatethe anchor and assigned carriers.
 12. A method to be performed by a useragent, the method comprising the steps of: a. performing capabilitynegotiations with an access device using three bit HPI to identify a DCIformat/communication protocol and corresponding maximum HPI bit count;and b. where the maximum HPI bit count is greater than three,communicating using the maximum HPI bit count.
 13. A mobile user agentfor use in a multi-carrier communication system comprising: a processorprogrammed to perform the steps of: designating a first subset of theHPIs as shared HPIs wherein each shared HPI designates a HARQ processirrespective of which of a plurality of system carrier frequencies areused to transmit a traffic packet; and designating a second subset ofthe HPIs as non-carrier-shared HPIs wherein each non-carrier-shared HPI,in conjunction with the carrier frequency used to transmit a trafficpacket, designates a carrier frequency unique HARQ process.
 14. The useragent of claim 13 wherein the processor is further programmed to performthe steps of: receiving an HPI at the mobile user agent; receiving afirst traffic packet via a carrier frequency at the user agent that isassociated with the HPI; where the HPI is a first subset HPI: (i) usingthe HPI to identify a HARQ process associated with the first trafficpacket irrespective of the carrier frequency used to transmit thetraffic packet; and (ii) providing the first traffic packet to theidentified HARQ process; where the HPI is a second subset HPI: (i) usingthe HPI and the carrier frequency on which the first traffic packet wasreceived to identify a carrier frequency specific HARQ processassociated with the first traffic packet; and (ii) providing the firsttraffic packet to the carrier frequency specific HARQ process.
 15. Theuser agent of claim 14 wherein the first traffic packet is received on afirst carrier frequency and a first HPI associated with the firsttraffic packet includes a first subset HPI, the processor furtherprogrammed to perform the steps of receiving a second traffic packet atthe mobile user agent on a second carrier frequency where an HPIassociated with the second traffic packet is the first HPI and,providing the second traffic packet to the HARQ process that receivedthe first traffic packet.
 16. A user agent for use in a communicationnetwork, the user agent comprising: a processor programmed to performthe steps of: a. designating one carrier as an anchor carrier; b.designating a plurality of carriers as assigned carriers, wherein atleast one of the plurality of assigned carriers is designated as aninactive carrier; and c. receiving a command on a control channel of theanchor carrier, the command resulting in changing the designation of atleast one of the at least one inactive assigned carriers to an activeassigned carrier.
 17. The user agent of claim 16 wherein the command isa PDCCH for a DCI packet including a particular HPI.
 18. The user agentof claim 16 wherein the processor is further programmed to perform thesteps of changing the designation of the active assigned carrier to aninactive assigned carrier after a timer expires.
 19. A user agent foruse in a communication system wherein the user agent comprises: aprocessor programmed to perform the steps of: a. performing capabilitynegotiations with an access device using three bit HPI to identify a DCIformat/communication protocol and corresponding maximum HPI bit count;and b. where the maximum HPI bit count is greater than three,communicating using the maximum HPI bit count.